The RS5 is the top performance model in Audi's A5 range, picking up the corporate 4.2-liter V8 that was deleted from the S4 at last year's facelift. This V8, however, is an upgraded version with 450 hp, rather than the 420 hp it produces in the Audi R8.
But the RS5 needs the extra power, weighing in at more than 4,000 pounds and bristling with Audi's comprehensive technical arsenal. With its tach redlined at a lofty 8,500 rpm, the V8's maximum piston speed is 26 meters per second (more than 5,000 feet per minute in U.S. terminology), which is right up there with Formula One engines.
Hooked to Audi's fastest-shifting seven-speed dual-clutch transmission, the V8 propels the RS5 to 60 mph in 4.5 seconds and will reach a governed top speed of 174 mph. The V8 exhaust cadence tends to understate the rotational speed, but it provides a truly awesome soundtrack.
Equipped with Audi's quattro all-wheel-drive system, the RS starts off with a 40/60 front-to-rear torque split. But it can shift power fore and aft as surface conditions dictate, and its rear sport differential provides torque vectoring in corners to help the car turn.
The Drive Select system dishes up various chassis and steering calibrations to broaden the car's capabilities. When equipped with the optional MMI telematics interface, Drive Select will allow individual tuning of steering effort, throttle response, transmission shift points, sport differential and exhaust note.
Wave brake rotors make their first appearance on an Audi with the RS, coincidentally at the same time the company announces its acquisition of Ducati. Wave-contour rotors are used to reduce mass and are common on motorcycles. Ceramic brakes are optional.
Fairly significant exterior changes visible on the RS include a honeycomb grille, wider sills, oval exhaust outlets, a larger rear diffuser and an active tail spoiler that pops up at 75 mph and snaps down at 50 mph. The car is offered with 19-inch wheels as standard, but there are beautiful 20-inchers available as an option.
Inside the car you find the flat-bottomed RS steering wheel, elegant split-style door handles and firmly bolstered sport seats. Optional equipment includes Audi Connect (which allows Wi-Fi hookup to eight devices), a Bang & Olufsen stereo, backup camera, and Google Earth navigation graphics with street view, which is new.
What is it like to drive?
Multiple personality operation has become de rigueur in high-end sport sedans and coupes, and this car is no exception. We crept through heavy San Francisco traffic and cruised its freeways in luxurious comfort, then circulated the undulating contours of Sonoma Raceway, where the RS5 deploys all its high-performance credentials to good effect.
With its Drive Select system switched to the dynamic mode, the car corners with little roll or pitch, yet it turns in well and even rotates when trail-braked enthusiastically into corners. A little steady throttle helps to stabilize the car through Sonoma Raceway's tricky downhill esses as the rear axle overdrives its outer wheel to generate yaw.
Even with the steel brakes the car stops pretty well for a two-tonner, and we did not experience any fade. Best of all is the stirring thunder from the exhaust at full power, and the brief burps as the injection cuts during gearshifts. It's not hard to feel Audi's motorsport pedigree in the RS5's responses, because the handling balance is a great compromise between stability and responsiveness.
Naturally, with 450 hp, its straight-line performance is impressive. Out in the real world, the only glitches we noticed were the sometimes magnetic sense of the electric power steering and an occasional abrupt downshift while we were rolling to a halt. The transmission once declutched during a long uphill stop-and-start sequence, allowing the car to roll backward.
But it's an indulgent ride in every way, from the tasteful interior to its stylish exterior to its virile performance.
Do I want one?
If this car meets your needs on paper, it will likely fulfill them on the road. At nearly $70,000, it isn't cheap. But nor does it shortchange the driver in any way. Fast, handsome and capable, the RS5 is rolling confirmation of Audi's rising role in the automotive world.
On Sale: Now
Base Price: $68,900
Drivetrain: 450-hp, 317-lb-ft, 4.2-liter V8, seven-speed dual-clutch transmission.
Curb Weight: 4,009 lb (mfr)
0-60 mph: 4.5 sec (mfr)
Fuel economy: 16/23/18 mpg
Read more: http://www.autoweek.com/article/20120808/carreviews/120809862#ixzz2CeoxNPtr